Track-circuit system



W. W. MACFARLANE.

TRACK CIRCUIT SYSTEM. APPLICATION F i. D SEPT- 20. wwfnsnawzo uov. 11.1920.

. 1,383,319, Pat ntedJuly 5, 1921.

a trainin a block section for lR ILLLJi I W. IiIAfiFARLlJANE, 31 ELKZNS PARK.

NS'YLVANIA, AESSIGNOE,

no Mac- EARLANE COMMI NIGATIUNS CORPQRATIQISI, 9F NE'W N. Y. A COR JRATION mil-mammoth,-

original application filed ii-flay i, 1915, No. 35,305.

Specification of Letters Ia cent.

Potential ullul 55, .l

Divided and this application filed September 20, 1917, Serial No. 192,258. Renewed. November 11, 1920. Serial No. 423,483.

To all whom it may concern:

Be it known that l l l innran il ilac- FARLANE, a citizen of the United in and l a resident of Elkins Park, in the con; of Montgomery and State of lennsylvania have invented certain new and useful Ill'la PIOVEH IQH'tS in Tracl-r-Circuit Systems, of which the following is a specification.

This invention relates to a system of track circuits particularly adapted for use in con-- nection with a system cl train control such as is disclosed in application Ser. llo. 95305 filed May 4, 19m, and renewed as Scrial No. 211,669, Jan 12; 1918; again renewed as Serial No. 2 l'l',867, Aug. 1, 1918; and again renewed as Serial No. $280,194, Mar. 1, 1919, of which this application is division.

The prin ipal object of the invention is to I provide a system of track circuits by means a train along a. track in either direction can be continuously and automatically controlled Without the use of ramp rails or stationary contacts other than the track rails. k

Vlith this, and other objects in View, the invention consists principally in the provision of means controlled by the presence of supplying current to the rails of the section to control the passage of a train. therethroughl Another feature of the invention is the provision of means for controllingthe supply of the train controllil-rc current to the train occupied block by the trallicconclition of the block s'cqtion next in advance regardless of the direction of travel of the train.

T he track circuit system disclosed is particularly adapted for use on a single track rail- Way. In addition to the ordinary normally closed track circuit in each block section, other normally open circuits are employed that are adapted to furnish to the rails oi the block train controlling current of a dilieren character than that supplied. by the normally closed circui Either alternating or direct of which the movement of current may be used in both the normally cte "zit-g current 13 tlther features of the invention will be referred to as the specification proceeds.

in the drawing there is represented a general diagrannnatic View of a track circuit system embodying the invention.

in the track circuit system illustrated the track rails l and 2 are divided into suitable block sections A, B, C, l3 and E which are insulated from each other in the usu manner. .ln the form shown, each block has normally impressed thereon an alternating current supplied by the transformer 3 connected across the line conductors t and The supply conductors {3 and 7 connect the secondary of the transformer to the rails at points near the middle of each block section. A non inductii'e resistance 8 is preferably interposed in the conductor 6 to nrcvcnt an excessive flow of current from thetransforl'ncr when a train is bridging the rails near the points of connection of the supply conductors 6 and 7 therewith.

Each block section. is provided with two alternating current track relays 9 and 10 connected to theails at the ends of the block through the conductors ll lfl and 33-434 respectiyely and adapted to he normolly energized by current irom' the transformer 3 When the block is not occupied by a train, in a manner well-known the signaling art. These track relays are prefer ably of the type which will respond only to a given frequency which, of course. will he that characteristic of the current supplied by the transformer 3. and will theretorche immune to direct current or to alternating current of a clili'crent frequency from that in connection with which they are designed to operate. If found (lesi able, some form of condenser Knight be provided in the connection between each alternating current relay and the track to prevent direct current from interfering with these relays.

block have also at opposite curls ot the o'ltdirect curr l3 and current for (i ii'rolling suitabletrain governing: devices 5 humbly .uiounteo on the locon'iotive oi tlu sin and a 'lar e volume.

The source 13 is connected to the track rail 1 through the conductor 15 and to the track rail 2 through the conductor 16, contacts 17, conductor 18, contacts 19, and conductor 20 including resistance 21 to rail 2. The contacts 17 are adapted to be bridged by the circuit closer 22 which isadapted to be held out of engagement with the contacts when the track relay 9 is energized. When the relay 9 is deenergized, as by the shortcircuiting effect of a train in the block, the circuit closer 22 is moved by the action of gravity into engagement with the contacts 17. Normally the circuit including the source 13 is open at the contacts 17 and is closed at this point coincidently with the entrance of a train into the block and upon the consequent de'e'nergization of the track relay 9.

The contacts 19 in the circuit through the source 13 are normally bridged by a circuit closer 24 controlled by the track relay 10 of the adjacent end of the adjoining block. Theaction of gravity will move the circuit closer 24 out of bridging engagement with the contacts 19 upon'denergization of relay ,10 caused by the 'bresencc of a train in the-corresponding block. Thus, under norrnal conditions,-that is, when no train is in either of two adjacent blocks,the circuit through the source 13 of one block is open at. the contacts 17 and closed at the corn tacts 19.

At the other end of each block the source of current 14 is connected through the con.- ductor 26 to the track rail 1 and through the conductor 27, contacts 28, conductor 29, contacts 30, and conductor 31 including the resistance 32 to the track rail 2. The com tacts 28 are adapted to be bridged by the circuit closer 22 when the relay 9 of the adjacent end of the adjoining block is energized, while the contacts 30 are adapted to be bridged by the circuit closer 24 wnen the track relay 10 is deiinergized.

It will be apparent. that, when the insulated blocks on both sides of any given block are unoccupied by a train, the contacts of the train control circuits of the given block which are under the control of the relays in the adjacent blocks will be closed. Consequently, a train which may be present in the given block will have current supplied. to its controlling device by the closed control circuit at the end of the block which it is approaching, since the contacts of the control circuits that are governed by the train-occupied block are also closed because of the deiinergization of the track relavs 9 and 10. a

It will be clear also th Specifically, the circuit 0" rent is supplied to the left-hau B and thence to the train. ()Olltl'i E on the locomotive of the tr; traveling through that block, is as follows: battery 13, conductor 16, contacts 1?, bridged by the circuit closer 22, conductor contacts 1% bridged by circuit closer 2%, conduct-or 21) including resistance 21, track in 2 contact member 37 in engagement with rail 2, coil 35, contact member 36, track rail. 1. and conductor 15 back to battery The current supplied by the c" uit at the rear of the train will have no e'l set on the coil 35 of the controlling device carried by the locomotive because of the shunting effect of the wheels and axles of? the train which are between the contact members 36 and 37 and the source at the roan it will be clear, therefore, that a. train enter ng the will itself be stopped because ity to take current from the circu t forward end of the block since ii will of course be open at the hreak com trolled by the train in the block ahead. Consequently, when two trains are proceed ing along the track in the same direction the forward train will not have its progress restricted by the presence of the train in the rear, While, on the other hand, the train to the rear cannot advance into the bloc-kc immediately to the rear of the one eiiccupied by the forward train. There must always be, then, in" the track circuit system disclosed, an intervening clear bloclr between two trains traveling in the direction. so that a following train can by no possiin advance to cause a' rearend collision therewith.

In the case where two trains preaching each other on a single 1'. the train in an occupied lilo opens a break in the train control circuit ,ofithe block ahead, it Will'he clear that the approaching train will stopped soon as it enters the bloeltvahe of the first train at, since the second train opens the train control circuit iv the adjacent end of the block ahead of it, that the first train will also he stopped as soon as it enters'the block ahead oi? the second train.

To nialrelth'is clear let us assume that trains in blocks it and. ill are approaching each other. 'lhc presence of a train in block B will denergize relay 1i) and open the circuit through battery 13 of bloclr so th 1, when the train in bio-sir D reachebl k (,1, the controlling device on this train tied} lies it the left-hand end-oi? iii-1e lcloclz.v

co open "b 1e conlrolllne" J effect of this is at the I'lgl3.i3-llfill(l end of block mus bring the "are in in t-liseblocii.

This lOI'D '13; about as it is norinaliy supplied to me rails eriglit-liand end block fire en;-

l-i by Way of conductor 27., contacts ien loriclgecl by circuit closer 2%,"00111- if: 29, contacts loriclgecl by circuit i 24h because of che cleiiergized condi- 1 of relay l0, conductor 31 including renee 32, track rail 2, conceive member 37, 35, contact member 36 rail 1 and -con- :1' 26 loeclr "to befiiery lei. 1%; will be the press ire of the brain in block (3' break this circuit by (lenergizing relay 3 i ll permitting the circuit closer 22.130 out of engagement with contacts 238. interruyption of the supply of current batizeity let to bloclgll will. automatibring the train in, block '3 'lo e slop. 'erefore not only will train approachfrom the rear )pecl when "less the block iii1moclieelyio the rear of main-occupied block, but also both of the caching trains will be stopped ininiecliupon entrance of either train into the hoe; immediately ahead of ihe other train, "esull; oi this is that no irain can approach than 5 block to another train regard of Whether the oitliec train is running or away from fihe fire, train or is moving all all. Also, of two "trains runin she same clirecibion the: following Krill be prevented from epproeciiing Nixie clengeronc 'pi'onimiiay the train While train in :iclvmice which is ,nizly tendiiigto Withdraw from What 1c become e dangerous position, will so reetricibionwliate er placed upon its meet by lhe approach Of thG trein fol, Ii; will accordingly be obvious that, crein, it travels, creel/es and carries it e giroieclive zone than exeende gh the itilocli inmieilieicly to the rear lhe block immediately elieeil oi "the occupied clocln and thereby serves nt tl e approach of two trains io 21; on Wl'i/l'llll e bloclilengtli of each other, claim in eleclric creil'iocont-rolling sys'em prising: we; r liviclecl ineo insul secl ions, means for supplying current one; a, certain characteristic to the rails llifiii'ni /(lifiim the ends of each section; a circonlrollcr all each cool of each section -(l. by current from said current supply 111611-3153, and means "for su'yplying curiicvinp; a different characteristic to both lsof a train-occupied seclion to control the peseege of a irein thQTBtlllmlgll when the connected lo the mile and concircuit controllers it the adjacent ends of the avclyoinlng seciions are energized.

An electric trafiic-controiling system coniprislngc track mile divided into insulaced sections, means for supplying currenthaving 2 certain characteristic ,fio the rails of each section, a circuit controller at each end. o'l each section. electrically connected to the rails and controlled by current from said curreni; supplying meens, and means for supplying current having a, clifif erent characteristic to the rails at the exit end of e train-occupied section to control the passage or" 2, train tlieretlirougli when the circuit controller in,- the entrance end of the next adjoining section is energized and regardless of the direct-ion of travel.

3, An electric Mellie-controllin system. 1

comprising: crack rails divided into insulated sections, meansfor supplying alternating current to the riiils of each section, a. circiiit controller for each section electrically connected to the rails thereof and con trolled by-current fmm said eliernating current supplyingmeene,and means for supplyi'og direct current to the rails at, the exit end oi? e train-occupied section to control a train therein when the circuit controller at the entrance end of the next adjoining section is energized.

l. An electric lreilic-controlling sys lcm comprising: creel; rails divided into insulaced sections, means for supplying elte'rnzio ing current tojhe mils of each section, a rereley for E-ficllSECl-iOIl controlled. by current from said alternating current supplying source, and meeneoontrollecl by each relay for sop-plying direct current to the rails of the next a'cljo-ining section.

5 An electric trofiic-conlrolling system comprising: track rails divided into ins i1 lfliiiiil; iiig current to the rails of each. section a, reley at the entrance end of each section controlled by current from said zilternziling current, supplying means; and means controllecl by each relay for supplying direct secfs-i.o-ns means for supplying alternat-' current to the milsvot' the exil end of the next ecijoining section.

6. An electric itraffic-controlling system comprising: track mils divided into insulated sections, means -for supplying alternating current to the rails of: each section, a, relay at each end of each section electrically connected to the rails and controlled by current from said alternating current enppiying means, and means controlled by saicl relays for supplying direct current to the rails of the adjoining. sections.

7. An electric trellic-controliing system comprising: track mile divided into in; suleted sect-ions, means for supplying alternating current to the rails of each section, a;

relay each end of each section electrically connected to the rails and controlled by current from said current means controlled one of said relays for supplying direct current to the rails at the adjacent end of the adjoining section, and means controlled by the other relay for supplying direct current to the rails at the adjecent'end of the other adjoining section.

8. An electric traffic-controlling system comprising: track rails divided into insulated sections, means fonsupplying alternating current to the rails of each section, a circuit controller at the entrance end of each section electrically connected to the mils thereof and controlled by current from said alternating current supplying means, and

supplying means,

means for supplying direct current to the rails at the exit end of a train-occupied section to control the passage of a train therethrough when the circuit controller at the entrance end of the next adjoining section is energized. I

9. An electric trafiic-controlling system comprising: track rails divided into insulated sections, means for supplying alternating current to the rails intermediate the ends of each section, a relay at each end oil each section electrically connected to the rails and controlled by current from said current supplying means, and means for supplying direct current to both ends of a trainoccupicd section to control the passage of 2% train tlicrethrougli when the relays at the adjacent ends cf the adjoining sections are QllBI'glZfifl.

10. An electric traffic-controlling system comprising; track rails divided into in su ated sections, means for supplying alternating current to the rails of each section, a. relay at each end of each section electrically connected to the rails and controlled by cur rent from said alternating current supplying means, and means for supplying direct current to'tlie rails at the exit end of a train occupied section to control the passage of a. train theretlirough when the relay at the entrance end of the next adjoining section is energized and regardless of the direction of travel.

' 11 A system of train control comprising: a track divided into insulated blocks, means for continuously supplying current of a certain characteristic to the rails of each block, a track relay for each block normally energized by said current, and means controlled jointly by the relay in a. given block and the relay in the block next in advance for supplying current of a, different characteristic to the rails of the given block to control the passage of a grain tlieretlirougli.

Signed at New York, in the county of New York and State of New York, this 18th day of Septe nber, 1917.

" it lLlJIAll/l W. MAGFARLANE. 

